terom@2: 
terom@2: import os.path
terom@2: 
terom@2: def get_site_url (script_name) :
terom@2:     """
terom@2:         Get the URL that points to the site root (i.e. where style.css is) using the given value of SCRIPT_NAME
terom@2: 
terom@2:         /foo/bar/quux.py                -> /foo
terom@2:         /~terom/qmsk.net/site/index.py  -> /~terom/qmsk.net
terom@2:         None                            -> /
terom@2:     """
terom@2:     
terom@2:     if script_name :
terom@2:         return os.path.dirname(os.path.dirname(script_name))
terom@2:     else :
terom@2:         return "/"
terom@2: 
terom@2: def get_page_path (path_info, default) :
terom@2:     """
terom@2:         Get the path of the page that was requested, or the given default is empty/invalid.
terom@2:         The path will never begin with an /.
terom@2: 
terom@2:         /quux       -> quux
terom@2:         /           -> <default>
terom@2:         None        -> <default>
terom@2:     """
terom@2:     
terom@2:     if path_info :
terom@2:         # remove prefixed slashes
terom@2:         path_info = path_info.lstrip('/')
terom@2: 
terom@2:     if path_info :
terom@2:         return path_info
terom@2:     else :
terom@2:         return default
terom@2: 
terom@2: 
terom@2: class Request (object) :
terom@2:     # The name of the site itself, this can be used to reference e.g. style.css
terom@2:     site_url = None
terom@2: 
terom@2:     # The page root url, for links to pages
terom@2:     page_root = None
terom@2: 
terom@2:     # The full path to the requested page
terom@2:     page_path = None
terom@2:     
terom@2:     def __init__ (self, environ, default_page='main') :
terom@2:         self.site_url = get_site_url(environ.get("SCRIPT_NAME"))
terom@2:         self.page_root = environ.get("SCRIPT_NAME")
terom@2:         self.page_path = get_page_path(environ.get("PATH_INFO"), default_page)
terom@2:     
terom@2:     def page_name_parts (self) :
terom@2:         """
terom@2:             Returns a list of page name components
terom@2:         """
terom@2: 
terom@2:         return self.page_path.split('/')
terom@2: 
terom@2:     def page_name_prefixes (self) :
terom@2:         """
terom@2:             Iterate over the components of the page name, yielding (prefix, suffix) pairs
terom@2:         """
terom@2:         
terom@2:         prefix = self.page_name_parts()
terom@2:         suffix = []
terom@2: 
terom@2:         while prefix :
terom@2:             yield ('/'.join(prefix), '/'.join(suffix))
terom@2: 
terom@2:             suffix.insert(0, prefix.pop(-1))
terom@2: